So now, it should be clear that the NWS tornado forecast products ... from outlooks to warnings ... cannot be considered 100% accurate in all respects but will always involve uncertainty. Furthermore,, decision-makers must consider other, non-meteorological issues in making their choices for how to react to a given situation so that it makes no sense to have some rigid rules for what choices to make. Decision-makers must, therefore, invest considerable effort in "situation awareness" - they have to be deeply committed to staying informed about what is always an evolving situation. The ultimate proper choice (i.e., the ex post facto "right decision") can change literally from one minute to the next as a tornado event unfolds.
With regard to school closings, what are some of the non-meteorological factors involved? I make no claim to be able to list them all, here. A big factor concerns the time of day. If the school is closed on the basis of the forecast/warning, should the children stay at school or go home? If the schools closes early and the children are sent home, will one or both of the parents of the children be at home? What is the state of construction quality associated with the children's homes - do they live in a mobile home or a flimsy frame home or a multistory multiple family home? How much time before an approaching tornado hits the school? Are the kids in class or at recess outside or waiting for buses to take them home, with parents waiting for some of them (or on the way to pick them up)?
What sort of protection does the school actually offer and will it be adequate for a strong or violent tornado, should they be unlucky enough to be in the path of such a storm? Does the school have a tornado plan? Assuming they have one, has the school's tornado plan been vetted by structural engineers and/or meteorologists so that it's known to be the best they actually can do with the existing structure? Is adequate shelter available anywhere in that school and who decided it was indeed adequate? If the school has sheltering inadequacies, can they afford the necessary modifications, up to and including purpose-built tornado shelters? I've seen plans at schools that are quite flawed and could eventually lead to a disaster. I've seen schools that, without structural changes, have no local capable of occupation by the entire population of the school that would provide adequate shelter - only the least bad among all their sheltering options.
Have regular tornado drills been done at least once per year? Are there means by which a school's decision-maker can be situation aware during a volatile weather situation - a weather radio and/or some internet connection that is being dedicated to weather situation awareness? Is the decision-maker trained well enough to make such difficult life-and-death decisions in the face of a complex, rapidly-changing hazard? Does the decision maker understand all the options and know their weak and strong points?
Moreover, as discussed in my first post on this topic, the tornado threat changes continually. But the vulnerability of some segments of a school's population varies. Physically handicapped people require more time to reach and enter shelter locations than the able-bodied, so they might have to commence their tornado precautions earlier than the rest of the group. Has all that been accounted for in the tornado plan?
Although this discussion is about school closings in particular, many similar statements are valid for churches, businesses, shopping malls, recreation areas, entertainment venues, and so on. For none of them is it trivially obvious what choices a decision-maker might have. Schools in session have been hit infrequently over the years, fortunately, but when they are hit while in session, the results can be tragic. And the same goes for all the other public and private locations where people might be concentrated in relatively high numbers. How many of those places have a tornado plan that's familiar to the occupants and easily implemented on relatively short notice? How many even have a person designated as the tornado decision-maker (i.e., an emergency manager) who is trained and equipped for the task? What if their designated decision-maker isn't there for some reason - do they have a properly prepared backup?
If the goal is to make the nation "weather ready", it's going to require a lot more than a few catchy slogans. The certification of weather readiness requires some stringent milestones, not just a few simple requirements. Being truly weather ready is a complex task that has many facets to be considered. A knee-jerk response based on some simple criterion (such as being in a tornado watch or not) is not really demonstrating practical weather readiness or adequate preparation.
Thursday, March 3, 2016
Tuesday, March 1, 2016
School closings in tornado hazard situations, Part 1
Recently, my colleague Dr. J Marshall Shepherd, has raised questions about policies regarding school operations during tornado situations. This issue is far from simple. It involves many complex topics and I want to discuss at least some of those topics. This will be somewhat longer than my typical blog, but it necessitates some detail. My bottom line is that any particular "answer" to Marshall's questions is extremely unlikely to be appropriate in all possible circumstances. In other words, I doubt seriously there's any "one size fits all" procedure for deciding what to do. Therefore, any decision regarding school responses to a threatening tornado situation depends strongly on the circumstantial details. And that includes not only the choices by the school administration, but also all the individual families including the schoolchildren.
First, a review of products from the National Weather Service [NWS]: the Storm Prediction Center (SPC) in Norman, Oklahoma issues various severe weather forecast products from a few hours in advance of a hazardous storm event, to several days ahead. The quality and accuracy of their forecasts have been improving over the decades. Their forecasts are not perfect but they can provide substantial value for decision-makers when used properly.
That raises an interesting point - at least interesting to me and some others - just how do decision-makers use a weather forecast that is inevitably uncertain, especially in terms of intensity, and temporal/spatial specificity (i.e., exactly when, where, and how strong will the event be?). It isn't possible for any forecast by anyone to provide such detail accurately and consistently. How does a user of this information make use of forecasts if it's known (and it is) that all forecasts have greater or lesser uncertainty. If the forecasts were perfectly accurate in all details, then the decision-maker's decision is made by the forecaster! The user then would know exactly what will happen and can make decisions easily. I understand why most users want this to be the case, even though they know better. People in Hell want a glass of ice water, too! No forecaster can do this, so it's illogical to expect that it is possible.
Moreover, a decision-maker must incorporate more information than just the weather forecast in making a decision -- factors that public sector (i.e., NWS) forecasters in general know little or nothing about. Some decision-makers, because of their circumstances, need a lot of advance warning in order to take appropriate action. Others can get by with much less lead time. Some have prepared shelter positions at immediate hand, others do not. Every user has unique circumstances. There's no way for NWS forecasters to know all the external factors that govern a weather forecast user's needs, so the forecasts simply can't be used as if they were somehow perfect. Perhaps a few user/decision-makers might be able to pay for the services of a private sector forecaster to make their weather decisions for them based on shared information so the forecasts know precisely what are their needs, but that's just not possible for NWS forecasters. Instead, NWS forecasters provide a forecast that is their best estimate of what will happen, and - ideally - supply some understandable information about the uncertainties of their forecast. A user then - ideally - merges that forecast with all the other information needed to make a decision.
Consider the implications of a Severe Storm Outlook issued by the SPC: this product delineates the area expected to experience severe weather a day or more in advance, to allow users to begin to prepare for the possibility of experiencing a hazardous storm. For any given location within the area designated, during the time when the forecast is valid, there is some generally unknown probability of experiencing that hazard, but the SPC seeks to assign a probability based on their understanding of the specific weather situation. In general, it is quite far from a time/space/intensity-specific prediction, of course. Even a 5% probability at this point in the weather situation is actually a relatively high value. On any given date, the probability of a severe weather event on the average is far below that 5% value! In most circumstances, the odds of any given location within the outlook area experiencing a tornado hazard is too low to take any actions, but users might best be served by preparing to take action when/if a hazardous situation arises.
When the weather situation evolves toward the imminent development of severe weather, the SPC usually issues a Severe Storm Watch that includes some information about the specific probability of a tornado within the space-time volume of the watch, and also some indication of the expected intensity of any tornadoes that might occur. This can include what is described as a Particularly Dangerous Situation (a so-called PDS Watch) that includes the potential for long-track, violent tornadoes. In the usual PDS tornado watch, the probability of having a significant tornado somewhere within the watch increases to some value, perhaps as high as 80%. With such a high probability, this might be sufficiently threatening for some users (those whose protective actions require extra time), but certainly not all, to commence their tornado precautions.
Finally, if a tornado has been detected in some way (often based on radar information), local NWS offices may issue a tornado Warning. Even in such cases, any specific location ahead of the tornado may or may not be hit. The typical size of a tornado-warned area is considerably less than that of the typical watch and the existence of a tornado is of far less uncertainty than that associated with a watch, so most people within the warned area are well-advised to take tornado precautions, but even in this dangerous situation, there is no guarantee of anything: a tornado could change intensity, dissipate, or swerve off in a new direction. Most long-track violent tornadoes roll along a more or less straight path for many minutes (up to an hour or more), but each storm case is different and not all tornadoes are "typical".
... to be continued
First, a review of products from the National Weather Service [NWS]: the Storm Prediction Center (SPC) in Norman, Oklahoma issues various severe weather forecast products from a few hours in advance of a hazardous storm event, to several days ahead. The quality and accuracy of their forecasts have been improving over the decades. Their forecasts are not perfect but they can provide substantial value for decision-makers when used properly.
That raises an interesting point - at least interesting to me and some others - just how do decision-makers use a weather forecast that is inevitably uncertain, especially in terms of intensity, and temporal/spatial specificity (i.e., exactly when, where, and how strong will the event be?). It isn't possible for any forecast by anyone to provide such detail accurately and consistently. How does a user of this information make use of forecasts if it's known (and it is) that all forecasts have greater or lesser uncertainty. If the forecasts were perfectly accurate in all details, then the decision-maker's decision is made by the forecaster! The user then would know exactly what will happen and can make decisions easily. I understand why most users want this to be the case, even though they know better. People in Hell want a glass of ice water, too! No forecaster can do this, so it's illogical to expect that it is possible.
Moreover, a decision-maker must incorporate more information than just the weather forecast in making a decision -- factors that public sector (i.e., NWS) forecasters in general know little or nothing about. Some decision-makers, because of their circumstances, need a lot of advance warning in order to take appropriate action. Others can get by with much less lead time. Some have prepared shelter positions at immediate hand, others do not. Every user has unique circumstances. There's no way for NWS forecasters to know all the external factors that govern a weather forecast user's needs, so the forecasts simply can't be used as if they were somehow perfect. Perhaps a few user/decision-makers might be able to pay for the services of a private sector forecaster to make their weather decisions for them based on shared information so the forecasts know precisely what are their needs, but that's just not possible for NWS forecasters. Instead, NWS forecasters provide a forecast that is their best estimate of what will happen, and - ideally - supply some understandable information about the uncertainties of their forecast. A user then - ideally - merges that forecast with all the other information needed to make a decision.
Consider the implications of a Severe Storm Outlook issued by the SPC: this product delineates the area expected to experience severe weather a day or more in advance, to allow users to begin to prepare for the possibility of experiencing a hazardous storm. For any given location within the area designated, during the time when the forecast is valid, there is some generally unknown probability of experiencing that hazard, but the SPC seeks to assign a probability based on their understanding of the specific weather situation. In general, it is quite far from a time/space/intensity-specific prediction, of course. Even a 5% probability at this point in the weather situation is actually a relatively high value. On any given date, the probability of a severe weather event on the average is far below that 5% value! In most circumstances, the odds of any given location within the outlook area experiencing a tornado hazard is too low to take any actions, but users might best be served by preparing to take action when/if a hazardous situation arises.
When the weather situation evolves toward the imminent development of severe weather, the SPC usually issues a Severe Storm Watch that includes some information about the specific probability of a tornado within the space-time volume of the watch, and also some indication of the expected intensity of any tornadoes that might occur. This can include what is described as a Particularly Dangerous Situation (a so-called PDS Watch) that includes the potential for long-track, violent tornadoes. In the usual PDS tornado watch, the probability of having a significant tornado somewhere within the watch increases to some value, perhaps as high as 80%. With such a high probability, this might be sufficiently threatening for some users (those whose protective actions require extra time), but certainly not all, to commence their tornado precautions.
Finally, if a tornado has been detected in some way (often based on radar information), local NWS offices may issue a tornado Warning. Even in such cases, any specific location ahead of the tornado may or may not be hit. The typical size of a tornado-warned area is considerably less than that of the typical watch and the existence of a tornado is of far less uncertainty than that associated with a watch, so most people within the warned area are well-advised to take tornado precautions, but even in this dangerous situation, there is no guarantee of anything: a tornado could change intensity, dissipate, or swerve off in a new direction. Most long-track violent tornadoes roll along a more or less straight path for many minutes (up to an hour or more), but each storm case is different and not all tornadoes are "typical".
... to be continued
Donald Trump - my take on his message
I've been reluctant to join the chorus of those decrying the march of Donald Trump to his possible nomination as the 2016 GOP Presidential candidate. I probably don't have much new to add to the rising tide of denunciations, as the bizarre sideshow that is Trump threatens to destroy the GOP. We have seen some GOP politicians beginning to endorse Trump, even as other GOP politicians say they will oppose the candidacy of their own party's nominee if it's Trump! I feel for those moderate Republicans who have been pushed aside by the Tea Party religious reich clowns and grotesque "pro wrestling" style of the Trump campaign. It must have the feel of an approaching runaway train to them.
We're seeing the fruit of the deepening divisions in American society, where corporate greed has been nurtured by GOP politicians currying financial support from the wealthy by offering them a deregulated economy, massive tax breaks, and even welfare via bail-outs and subsidies, while the nation's infrastructure crumbles, vast sums literally are going up in smoke in pointless foreign wars that only benefit the arms manufacturers, and American freedoms are being surrendered in an atmosphere of carefully cultivated paranoia. GOP politicians keep doubling down on their thoroughly discredited "trickle-down" economics and "free market capitalism" that is little more than welfare for the rich. The middle and lower classes are feeling the pinch but somehow keep voting into public office the very scoundrels responsible for their woes.
Discontent with government is everywhere, and populism is on the rise - Trump is a fascist populist figure, blaming the political "establishment" for not having the will to "make America great again". Is it a coincidence that Bernie Sanders is a democratic socialist populist? I think not. Our nation is driving itself outward to the ends of the political spectrum. Perhaps not yet the extreme ends, but surely outward from the center. Compromise and cooperation in the governance of the nation have all but vanished in a torrent of denunciation and polarization.
Populism: any of various, often anti-establishment or anti-intellectual political movements or philosophies that offer unorthodox solutions or policies and appeal to the common person rather than according with traditional party or partisan ideologies.
The fact that Trump's campaign is virtually all show without any real content - claims of things he will do unaccompanied by any notion of how he will do those things - matters little, if at all, to his followers. His lies, his self-contradictions, his obscene language, his bullying, his massive ignorance, his colossal arrogance, his actual incompetence - none of that deters his fans. Trump has even claimed he could commit murder without shaking the loyalty of his supporters and he could very well be right about that! These folks are of a mindset that seems to associate with Hitler's brownshirts and Mussolini's blackshirts - they are crypto-fascists that long have lurked beneath the American facade of freedom and equality for all, ready to burst forth to follow a fascist dictator and do his bidding. Trump is that demagogue and they are willing to be his shock troops. A strutting, blustering dictator has a great need for those ready to do his dirty work of intimidating with violence on behalf of his cause, after all.
Finally, the "rise" of Trump has masked the radicalization of the GOP by the Tea Party "revolution". Should Trump not succeed in grabbing the nomination, then the GOP candidates remaining viable in the race for the nomination are uniformly pathetic and seemingly committed to advancing the process of transforming the US into a christian theocracy, all in the name of "family values (from "God"), capitalism, and patriotism". While I'm not all that crazy about the Democratic candidates, either one is vastly preferable to me than any of the GOP clown car occupants. The moderate Republicans have been pushed aside in the march to drive the GOP car off a cliff. Trump is the catalyst for this but not the cause. We are doing it to ourselves.
We're seeing the fruit of the deepening divisions in American society, where corporate greed has been nurtured by GOP politicians currying financial support from the wealthy by offering them a deregulated economy, massive tax breaks, and even welfare via bail-outs and subsidies, while the nation's infrastructure crumbles, vast sums literally are going up in smoke in pointless foreign wars that only benefit the arms manufacturers, and American freedoms are being surrendered in an atmosphere of carefully cultivated paranoia. GOP politicians keep doubling down on their thoroughly discredited "trickle-down" economics and "free market capitalism" that is little more than welfare for the rich. The middle and lower classes are feeling the pinch but somehow keep voting into public office the very scoundrels responsible for their woes.
Discontent with government is everywhere, and populism is on the rise - Trump is a fascist populist figure, blaming the political "establishment" for not having the will to "make America great again". Is it a coincidence that Bernie Sanders is a democratic socialist populist? I think not. Our nation is driving itself outward to the ends of the political spectrum. Perhaps not yet the extreme ends, but surely outward from the center. Compromise and cooperation in the governance of the nation have all but vanished in a torrent of denunciation and polarization.
Populism: any of various, often anti-establishment or anti-intellectual political movements or philosophies that offer unorthodox solutions or policies and appeal to the common person rather than according with traditional party or partisan ideologies.
To me, Trump is the voice of the ignorant, bigoted underclass of Americans who have heretofore felt muzzled by the imposition of what they see as "political correctness". Trump appeals to many of them because his candidacy legitimizes what they feel, saying for them what they thought they weren't being allowed to say. His act is one that resembles the papier-mâché faux morality play that is pro wrestling, where blustering villains try to intimidate strong-willed heroes, standing nose-to-nose in shouting matches, blowing spittle into each other's faces, and bashing their opposition with folding chairs. And of course, it's all a fake drama with no real content. I suspect the demographic supporting Trump probably has considerable overlap with the fan base for pro wrestling, albeit not a perfect match, of course. Bluster and bullying without any substantive content. And somehow, some people find that hogwash appealing.
The fact that Trump's campaign is virtually all show without any real content - claims of things he will do unaccompanied by any notion of how he will do those things - matters little, if at all, to his followers. His lies, his self-contradictions, his obscene language, his bullying, his massive ignorance, his colossal arrogance, his actual incompetence - none of that deters his fans. Trump has even claimed he could commit murder without shaking the loyalty of his supporters and he could very well be right about that! These folks are of a mindset that seems to associate with Hitler's brownshirts and Mussolini's blackshirts - they are crypto-fascists that long have lurked beneath the American facade of freedom and equality for all, ready to burst forth to follow a fascist dictator and do his bidding. Trump is that demagogue and they are willing to be his shock troops. A strutting, blustering dictator has a great need for those ready to do his dirty work of intimidating with violence on behalf of his cause, after all.
Finally, the "rise" of Trump has masked the radicalization of the GOP by the Tea Party "revolution". Should Trump not succeed in grabbing the nomination, then the GOP candidates remaining viable in the race for the nomination are uniformly pathetic and seemingly committed to advancing the process of transforming the US into a christian theocracy, all in the name of "family values (from "God"), capitalism, and patriotism". While I'm not all that crazy about the Democratic candidates, either one is vastly preferable to me than any of the GOP clown car occupants. The moderate Republicans have been pushed aside in the march to drive the GOP car off a cliff. Trump is the catalyst for this but not the cause. We are doing it to ourselves.
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